Telescoping binding posts



Nov. 15, 1960 F. STEARN EIAL 2,960,677 mmscopmc BINDING POSTS Filed Nov.21, 1958 Y 2 Sheets-Sheet 1 7 INVENTORS:

- FRANKUN A. STEARN \JONEL. P HOPK\N$ ATTORNEYS Nov. 15, 1960 F. A.STEARN EIAL TELESCOPING. BINDING POSTS 2 sheets-sheet 2 Filed Nov. 21,1958 FIG.

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FRANKLIN lii g T iim LKDNEL P. HOPKINS BY f%@%@ ATTORNEYS United StatesPatent TELESCOPING BINDING POSTS Franklin Andrus Steam, Westfield, andLionel Petgrave Hopkins, Summit, N.J., assignors to InternationalTelephone and Telegraph Corporation, a corporation of Maryland FiledNov. 21, 1958, Ser. No. 775,644

3 Claims. (Cl. 339-254) Our invention relates to telescoping bindingposts, being those wherein two relatively slidable parts are springloaded to cause an inserted electrical wire or conductor, to be grippedbetween them and retained in position. Principal objects of theinvention are to provide an improved binding-post construction of theforegoing character which permits a conductor to be readily insertedtherein and removed therefrom, and grips the inserted conductor firmlywithout injury thereto.

In known binding posts of the foregoing telescoping type, it iscustomary to telescope the parts against the pressure of a loadingspring until openings through the parts coincide to permit the insertionof a conductor through both openings. The inserted conductor is grippedbetween the parts when the initially applied force is removed. Aprincipal disadvantage of this type of structure is that the edges oftheopenings in the telescoping parts tends to impart a shearing'forceupon the conductor gripped between them. If the conductor is a wire of asoft metal, such as copper, it is nicked and partly sheared at thepoints at which it is gripped. As a consequence, relatively slightmovements of the ungripped portion of the wire sufiice to cause bendingand breakage at the nicked or partly sheared location.

According to the invention, the spring-loaded parts are secured togetherfor limited telescoping movement by a pin fixed in one of them andmovable in a slot through the other which intersects theconductor-receiving opening therethrough. The inserted conductor issecured in place by being gripped vice-like between the pin and a sidewall of the wire-receivingopening and of the slot, or both, wherebyundesired nicking and shearing action are avoided.

According to one feature of the invention, the side wall with which thenoted pin cooperates in gripping the inserted wire may have a shapedeparting sufficiently from a fiat surface that the gripping actionproduces a slight bend in an inserted small wire which enhances t thegripping action and the conductivity of the connection withoutsubstantial nicking.

According to a further feature, the telescoping parts may be of suchform that the wire or similar conductor to be inserted may be laid inplace sidewise rather than being inserted endwise, facilitatingplacement and rer'noval. V V A still further feature is that a conductormay be inserted at an acute angle to the longitudinal axis of thetelescoping parts, which is of distinct advantage in crowded quarterswhere direct side access to the binding post is difiicult.

The foregoing and other objects and features of our invention and themanner of attaining them will become more apparent, and the inventionitself will be best understood, by reference to the followingdescription of three embodiments of the invention taken in conjunctionwith the accompanying drawing, wherein Figs. 1 to 5 show a firstembodiment; Figs. 6 to 8 show a second 2,960,677 Pa tented Nov, 15,19 0

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2 embodiment; and Figs. 9 to 11 show a third embodiment:

Figs. 1 to 4 are respectively a top view, a left side view, a frontview, and a side sectional view of a binding post according to the firstembodiment, Figs. 3A, 4A, and 5 being two auxiliary views and a topsectional view;

Figs. 6, 7, and 8 are respectively a left-side view, a front view, and afront sectional view of the second embodiment; and

Figs. 9 to 11 are respectively a left-side view, a. front view, and aleft sectional View of the third embodiment.

First embodiment (Figs. 1 t0 5) Referring to Figs. 1 to 5, along withFigs. 3A and 4A, the binding post of the first embodiment comprises aprincipal stem-like portion A, loading spring B, thimblelike cup C, andpin D fixed in cup C to hold parts A and C slidingly together, since pinD extends through slot 7 through the upper stem portion 3 of fixedmemher A.

Fixed member A, consisting of upper stem 3, threaded lower stem 4, andhexagonal base 2, and fastened to insulating panel 1 by nut 9, mayconveniently be turned from a section of hexagonal rod.

Clip 10, with soldered local wire 12, is held on lower stem 4 by nut 11.a 7

Compression spring B surrounds upper stem 3 between base 2 and the loweredge of cup C, to hold the cup in its normal uppermost position, whereinriveted pin D carried by cup C engages the top of'slot 7 in upper stem3.

Conductor-receiving hole 6 through upper stem 3 intersects slot 7,conveniently at right angles, near the upper end of the slot. Cup Ccontains a conductor-receiving hole 5 which exposes hole 6r when cup Cis pushed down. a

To insert a conductor, such as the uncovered end of wire 8, into thebinding post of an electrical connection, cup C is pushed down againstthe force (say five pounds) of spring B until opening 5 in cup C exposesopening 6 in upper stem 3. Pin D is thereby carried down in slot 7 belowhole 6.

The end of a conductor, such as wire 8, may now be inserted through bothopenings 5 and 6, and above the lowered pin D. Cup C is now released andis moved up by spring B, carrying pin D upwardly within slot 7 intovice-like gripping contact with wire 8, pressing it against the upperside wall of openings 6 and 7. If the wire 8 is relatively small and isof soft copper, it curves, where gripped, into the upper portion of slot7, as shown best in Fig; 4A. The gripping action and electricalconnection are thereby enhanced without the occurrence of nicking orshearing. In this regard, it will be observed that receiving opening 5of the cup is shownsomewhat larger than receiving opening 6 through thestem. -This feature cooperates with the location of pin D in the cup,with its top surface higher than the lower limits of opening 5, toinsure that the inserted conductor is not gripped by the lower wall ofopening 5, thereby assuring the desired absence of shearing tendency.

vSecond embodiment (Figs. 6 t0 8) side milling 105, with an innerdownward extension 105a in place of opening 5, and providing upper stem103 with wire-receiving side milling 106, in place of through hole 6.Slot or milling 106 intersects one side of pin slot 107 near its upperend, as seen best in dotted outline in Fig. 6. 'When cup C1 is pusheddown against the force of spring B1, slot 106 is exposed by 105 and 105aas the cup C1 carries pin D1 down in pin slot 107. A conductor such as108 (Fig. 8) may now be introduced side- Ward into slot 106, throughslot 105, 105a. Alternatively, 108 may be inserted endwise to enter 105aand 106.

When cup C1 is then released and is moved upwardly by spring B1, itcarries pin D1 into contact with the inserted conductor 108 as shown inFig. 8, the conductor being gripped between the pin and the upper wallof slot 106. Since the slots 106 and 107 intersect slightly below thetop of 107, curving of the gripped conductor 108 may occur as describedand shown for wire 8, permitting cup C1 and pin D1 to rise slightlyhigher than their position shown in Fig. 8.

Third embodiment (Figs. 9 to 11) Referring to Figs. 9 to 11, the thirdembodiment of the invention is also generally similar to the firstembodiment but differs therefrom in that a wire or other conductor maybe inserted downwardly and inwardly into the binding post, to permit useof the binding post in crowded quarters, for example.

Items A2 to D2 and 202 to 208 of Figs. 9 to 11 correspond to items A toD and 2 to 8 of Figs. 1 to 5.

For diagonal insertion, cup C2 has conductor-receiving opening 205extending through the upper front edge at a desired angle (such as 45degrees) to its longitudinal axis. For through insertion, where desired,opening 205a is provided in the cap aligned generally with 205. Upperstern 203 has its wire receiving opening 206 inclined to the center lineof the upper stem by the noted angle, such as 45 degrees.

When cap C2 is pushed down against the force of spring B2, opening 206is exposed by openings 205 and 205a. A wire such as 208 may now beinserted from the right upper corner into and through openings 205, 206,and 205a as shown in Fig. 11.

When cup C2 is released, it is moved upward by spring B2, carrying pinD2 into contact with the inserted wire 208 as shown in Fig. 11, the wirebeing gripped between the pin and the upper wall of opening 206 in theupper stem. Since opening 206 and slot 207 intersect slightly below thetop of slot 207 the pin exerts a wedging action on the wire, enhancingboth the gripping effect and the electrical contact between wire andstem.

In the case of thin wires there may also be a tendency to a curving ofthe gripped wire as described and shown for wire 8.

While we have described above the principles of our invention inconnection with specific apparatus, it is to be clearly understood thatthis description is made only by way of example and not as a limitationto the scope of our invention.

We claim:

1. A binding post comprising a sleeve and a stem received therein for arelative telescoping movement between a normal position and aconductor-receiving position, a spring biasing the sleeve and stem tostand in and to return to said normal position, the stem having a guideslot extending through its longitudinal axis and elongated in itsdimension along the stem axis, a guide pin fixed with the sleeve andslidingly received within the guide slot, the guide pin being engageablewith the stem at one end of the guide slot to define said normalposition and acting with the guide slot to limit relative rotation ofthe stern and sleeve, the stem having a conductor-receiving openingwhich intersects the guide slot, the sleeve having a conductor-receivingopening which aligns with the conductor-receiving opening of the stem,to permit a conductor to be inserted through the conductor-receivingopening of the sleeve into the conductor-receiving opening of the stem,when the stem and sleeve are telescoped against the force of the springinto the said conductor-receiving position, the said opening of thesleeve being so located along the sleeve with respect to said opening ofthe stern that, on release of the stem and sleeve for said movementthereof by the spring toward the said normal position, the portion ofthe inserted conductor which intersects the axis of the stem is grippedbetween the guide pin and the said end of the guide slot, while there isno gripping of the inserted conductor between the stem and the sleeveitself.

2. A binding post comprising a sleeve and a stem received therein for arelative telescoping movement between a normal position and aconductor-receiving position, a spring biasing the sleeve and stem tostand in and to return to said normal position, the stem having a guideslot therein elongated in its dimension along the stem axis, a guide pinfixed with the sleeve and slidingly received within the guide slot, theguide pin being engageable with the stem at one endof the guide slot todefine said normal position and acting with the guide slot to limitrelative rotation of the stem and sleeve, the stem having aconductor-receiving opening which intersects the guide slot, the sleevehaving a conductor-receiving opening which aligns with theconductor-receiving opening of the stem to permit a conductor to beinserted through the conductor-receiving opening of the sleeve into theconductor-receiving opening of the stern, when the stem and sleeve aretelescoped against the force of the spring into the saidconductor-receiving position, the said opening of the sleeve being solocated along the sleeve with respect to said opening of the stem that,on release of the stem and sleeve for said movement thereof by thespring toward the said normal position, the portion of the insertedconductor which intersects the said guide slot is gripped between theguide pin and the said end of the guide slot, while'leaving the insertedconductor ungripped by the portion of the sleeve which defines the saidconductor-receiving opening thereof.

3. A binding post according to claim 2, wherein the saidconductor-receiving opening of the said stem intersects the said guideslot at a location axially displaced from the said end thereof, wherebya bending force is exerted on a said inserted and gripped conductorwhich tends to produce an offset in the gripped portion thereof.

References Cited in the file of this patent UNITED STATES PATENTS296,160 Goodbody Apr. 1, 1884 1,437,103 Hengstenberg Nov. 28, 19222,293,719 Eby Aug. 25, 1942 2,464,565 Evans et al. Mar. 15, 19492,651,671 Lanfear Sept. 8, 1953- 2,677,745 Leon May 4, 1954

